The objective of this project is to elucidate the mechanism of the induction of bladder cancer in the dog by the aromatic amines. The first goal is to determine the nature of the active urinary agent of these aromatic amines which is responsible for their carcinogenic effect on the bladder. Much progress in this direction has already been made. We have obtained evidence of the existence of a glucuronic acid conjugate of N-hydroxy-4-aminobiphenyl in the urine of dogs given 4-aminobiphenyl. This conjugate readily hydrolyzes in the urine to liberate N-hydroxy-4-aminobiphenyl which we believe to be the active urinary carcinogen. Efforts are being made to isolate and/or synthesize this metabolite. We will then study the release in the bladder of the active N-hydroxy compound, and the manner in which it penetrates and attacks the mucosal cells. The formation of similar metabolites of 1- and 2-naphthylamine will also be investigated. Gas chromatography, liquid chromatography and GC Mass Spectrometry are our primary analytical tools. The excretion of these metabolites in Rhesus monkeys, BDF-1 mice, rats and hamsters will be examined. The N- hydroxylation of aniline and 2-aminofluorene in the dog will be investigated. Further progress in the isolation of the glucuronide of N-hydroxy- 4-aminobiphenyl has been made. We have obtained small quantities of this metabolite in pure form. Preliminary investigations on BDF-1 mice indicate that this species does N-hydroxylate the aromatic amines.